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I2C: Modify the I2C driver for EXYNOS5

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This patch modifies the S3C I2C driver to suppport EXYNOS5.
The cahnges made to driver are as follows:
        - I2C base address is passed as a parameter to many
        functions to avoid multiple #ifdef
        - Channel initialisation is moved to a commom funation
        as it is required by i2c_init.
        - Hardcoding for I2CCON_ACKGEN removed.
        - Replaced printf with debug.
        - Checkpatch issues resolved.
        - Pinmux setting will be done in board/samsung/smdk5250/smdk5250.c
        to avoid repeated setting of gpio lines, as it have multi bus support.

Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Rajeshwari Shinde <rajeshwari.s@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
master
Rajeshwari Shinde 12 years ago committed by Heiko Schocher
parent 91dffb16ff
commit ab7e52bb24
1 changed files with 117 additions and 77 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 194
      drivers/i2c/s3c24x0_i2c.c

194
drivers/i2c/s3c24x0_i2c.c
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@ -27,10 +27,15 @@
*/ */
#include <common.h> #include <common.h>
#ifdef CONFIG_EXYNOS5
#include <asm/arch/clk.h>
#include <asm/arch/cpu.h>
#else
#include <asm/arch/s3c24x0_cpu.h> #include <asm/arch/s3c24x0_cpu.h>
#endif
#include <asm/io.h> #include <asm/io.h>
#include <i2c.h> #include <i2c.h>
#include "s3c24x0_i2c.h"
#ifdef CONFIG_HARD_I2C #ifdef CONFIG_HARD_I2C
@ -45,6 +50,7 @@
#define I2CSTAT_BSY 0x20 /* Busy bit */ #define I2CSTAT_BSY 0x20 /* Busy bit */
#define I2CSTAT_NACK 0x01 /* Nack bit */ #define I2CSTAT_NACK 0x01 /* Nack bit */
#define I2CCON_ACKGEN 0x80 /* Acknowledge generation */
#define I2CCON_IRPND 0x10 /* Interrupt pending bit */ #define I2CCON_IRPND 0x10 /* Interrupt pending bit */
#define I2C_MODE_MT 0xC0 /* Master Transmit Mode */ #define I2C_MODE_MT 0xC0 /* Master Transmit Mode */
#define I2C_MODE_MR 0x80 /* Master Receive Mode */ #define I2C_MODE_MR 0x80 /* Master Receive Mode */
@ -53,6 +59,10 @@
#define I2C_TIMEOUT 1 /* 1 second */ #define I2C_TIMEOUT 1 /* 1 second */
static unsigned int g_current_bus; /* Stores Current I2C Bus */
#ifndef CONFIG_EXYNOS5
static int GetI2CSDA(void) static int GetI2CSDA(void)
{ {
struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio(); struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio();
@ -77,16 +87,17 @@ static void SetI2CSCL(int x)
struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio(); struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio();
#ifdef CONFIG_S3C2410 #ifdef CONFIG_S3C2410
writel((readl(&gpio->gpedat) & ~0x4000) | (x & 1) << 14, &gpio->gpedat); writel((readl(&gpio->gpedat) & ~0x4000) |
(x & 1) << 14, &gpio->gpedat);
#endif #endif
#ifdef CONFIG_S3C2400 #ifdef CONFIG_S3C2400
writel((readl(&gpio->pgdat) & ~0x0040) | (x & 1) << 6, &gpio->pgdat); writel((readl(&gpio->pgdat) & ~0x0040) | (x & 1) << 6, &gpio->pgdat);
#endif #endif
} }
#endif
static int WaitForXfer(void) static int WaitForXfer(struct s3c24x0_i2c *i2c)
{ {
struct s3c24x0_i2c *i2c = s3c24x0_get_base_i2c();
int i; int i;
i = I2C_TIMEOUT * 10000; i = I2C_TIMEOUT * 10000;
@ -98,35 +109,75 @@ static int WaitForXfer(void)
return (readl(&i2c->iiccon) & I2CCON_IRPND) ? I2C_OK : I2C_NOK_TOUT; return (readl(&i2c->iiccon) & I2CCON_IRPND) ? I2C_OK : I2C_NOK_TOUT;
} }
static int IsACK(void) static int IsACK(struct s3c24x0_i2c *i2c)
{ {
struct s3c24x0_i2c *i2c = s3c24x0_get_base_i2c();
return !(readl(&i2c->iicstat) & I2CSTAT_NACK); return !(readl(&i2c->iicstat) & I2CSTAT_NACK);
} }
static void ReadWriteByte(void) static void ReadWriteByte(struct s3c24x0_i2c *i2c)
{ {
struct s3c24x0_i2c *i2c = s3c24x0_get_base_i2c();
writel(readl(&i2c->iiccon) & ~I2CCON_IRPND, &i2c->iiccon); writel(readl(&i2c->iiccon) & ~I2CCON_IRPND, &i2c->iiccon);
} }
static struct s3c24x0_i2c *get_base_i2c(void)
{
#ifdef CONFIG_EXYNOS5
struct s3c24x0_i2c *i2c = (struct s3c24x0_i2c *)(samsung_get_base_i2c()
+ (EXYNOS5_I2C_SPACING
* g_current_bus));
return i2c;
#else
return s3c24x0_get_base_i2c();
#endif
}
static void i2c_ch_init(struct s3c24x0_i2c *i2c, int speed, int slaveadd)
{
ulong freq, pres = 16, div;
#ifdef CONFIG_EXYNOS5
freq = get_i2c_clk();
#else
freq = get_PCLK();
#endif
/* calculate prescaler and divisor values */
if ((freq / pres / (16 + 1)) > speed)
/* set prescaler to 512 */
pres = 512;
div = 0;
while ((freq / pres / (div + 1)) > speed)
div++;
/* set prescaler, divisor according to freq, also set ACKGEN, IRQ */
writel((div & 0x0F) | 0xA0 | ((pres == 512) ? 0x40 : 0), &i2c->iiccon);
/* init to SLAVE REVEIVE and set slaveaddr */
writel(0, &i2c->iicstat);
writel(slaveadd, &i2c->iicadd);
/* program Master Transmit (and implicit STOP) */
writel(I2C_MODE_MT | I2C_TXRX_ENA, &i2c->iicstat);
}
void i2c_init(int speed, int slaveadd) void i2c_init(int speed, int slaveadd)
{ {
struct s3c24x0_i2c *i2c = s3c24x0_get_base_i2c(); struct s3c24x0_i2c *i2c;
#ifndef CONFIG_EXYNOS5
struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio(); struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio();
ulong freq, pres = 16, div; #endif
int i; int i;
/* wait for some time to give previous transfer a chance to finish */ /* By default i2c channel 0 is the current bus */
g_current_bus = 0;
i2c = get_base_i2c();
/* wait for some time to give previous transfer a chance to finish */
i = I2C_TIMEOUT * 1000; i = I2C_TIMEOUT * 1000;
while ((readl(&i2c->iicstat) && I2CSTAT_BSY) && (i > 0)) { while ((readl(&i2c->iicstat) & I2CSTAT_BSY) && (i > 0)) {
udelay(1000); udelay(1000);
i--; i--;
} }
#ifndef CONFIG_EXYNOS5
if ((readl(&i2c->iicstat) & I2CSTAT_BSY) || GetI2CSDA() == 0) { if ((readl(&i2c->iicstat) & I2CSTAT_BSY) || GetI2CSDA() == 0) {
#ifdef CONFIG_S3C2410 #ifdef CONFIG_S3C2410
ulong old_gpecon = readl(&gpio->gpecon); ulong old_gpecon = readl(&gpio->gpecon);
@ -170,27 +221,8 @@ void i2c_init(int speed, int slaveadd)
writel(old_gpecon, &gpio->pgcon); writel(old_gpecon, &gpio->pgcon);
#endif #endif
} }
#endif /* #ifndef CONFIG_EXYNOS5 */
/* calculate prescaler and divisor values */ i2c_ch_init(i2c, speed, slaveadd);
freq = get_PCLK();
if ((freq / pres / (16 + 1)) > speed)
/* set prescaler to 512 */
pres = 512;
div = 0;
while ((freq / pres / (div + 1)) > speed)
div++;
/* set prescaler, divisor according to freq, also set
* ACKGEN, IRQ */
writel((div & 0x0F) | 0xA0 | ((pres == 512) ? 0x40 : 0), &i2c->iiccon);
/* init to SLAVE REVEIVE and set slaveaddr */
writel(0, &i2c->iicstat);
writel(slaveadd, &i2c->iicadd);
/* program Master Transmit (and implicit STOP) */
writel(I2C_MODE_MT | I2C_TXRX_ENA, &i2c->iicstat);
} }
/* /*
@ -200,19 +232,19 @@ void i2c_init(int speed, int slaveadd)
* by the char, we could make it larger if needed. If it is * by the char, we could make it larger if needed. If it is
* 0 we skip the address write cycle. * 0 we skip the address write cycle.
*/ */
static static int i2c_transfer(struct s3c24x0_i2c *i2c,
int i2c_transfer(unsigned char cmd_type, unsigned char cmd_type,
unsigned char chip, unsigned char chip,
unsigned char addr[], unsigned char addr[],
unsigned char addr_len, unsigned char addr_len,
unsigned char data[], unsigned short data_len) unsigned char data[],
unsigned short data_len)
{ {
struct s3c24x0_i2c *i2c = s3c24x0_get_base_i2c();
int i, result; int i, result;
if (data == 0 || data_len == 0) { if (data == 0 || data_len == 0) {
/*Don't support data transfer of no length or to address 0 */ /*Don't support data transfer of no length or to address 0 */
printf("i2c_transfer: bad call\n"); debug("i2c_transfer: bad call\n");
return I2C_NOK; return I2C_NOK;
} }
@ -226,7 +258,7 @@ int i2c_transfer(unsigned char cmd_type,
if (readl(&i2c->iicstat) & I2CSTAT_BSY) if (readl(&i2c->iicstat) & I2CSTAT_BSY)
return I2C_NOK_TOUT; return I2C_NOK_TOUT;
writel(readl(&i2c->iiccon) | 0x80, &i2c->iiccon); writel(readl(&i2c->iiccon) | I2CCON_ACKGEN, &i2c->iiccon);
result = I2C_OK; result = I2C_OK;
switch (cmd_type) { switch (cmd_type) {
@ -238,16 +270,16 @@ int i2c_transfer(unsigned char cmd_type,
&i2c->iicstat); &i2c->iicstat);
i = 0; i = 0;
while ((i < addr_len) && (result == I2C_OK)) { while ((i < addr_len) && (result == I2C_OK)) {
result = WaitForXfer(); result = WaitForXfer(i2c);
writel(addr[i], &i2c->iicds); writel(addr[i], &i2c->iicds);
ReadWriteByte(); ReadWriteByte(i2c);
i++; i++;
} }
i = 0; i = 0;
while ((i < data_len) && (result == I2C_OK)) { while ((i < data_len) && (result == I2C_OK)) {
result = WaitForXfer(); result = WaitForXfer(i2c);
writel(data[i], &i2c->iicds); writel(data[i], &i2c->iicds);
ReadWriteByte(); ReadWriteByte(i2c);
i++; i++;
} }
} else { } else {
@ -257,19 +289,19 @@ int i2c_transfer(unsigned char cmd_type,
&i2c->iicstat); &i2c->iicstat);
i = 0; i = 0;
while ((i < data_len) && (result = I2C_OK)) { while ((i < data_len) && (result = I2C_OK)) {
result = WaitForXfer(); result = WaitForXfer(i2c);
writel(data[i], &i2c->iicds); writel(data[i], &i2c->iicds);
ReadWriteByte(); ReadWriteByte(i2c);
i++; i++;
} }
} }
if (result == I2C_OK) if (result == I2C_OK)
result = WaitForXfer(); result = WaitForXfer(i2c);
/* send STOP */ /* send STOP */
writel(I2C_MODE_MR | I2C_TXRX_ENA, &i2c->iicstat); writel(I2C_MODE_MR | I2C_TXRX_ENA, &i2c->iicstat);
ReadWriteByte(); ReadWriteByte(i2c);
break; break;
case I2C_READ: case I2C_READ:
@ -279,13 +311,13 @@ int i2c_transfer(unsigned char cmd_type,
/* send START */ /* send START */
writel(readl(&i2c->iicstat) | I2C_START_STOP, writel(readl(&i2c->iicstat) | I2C_START_STOP,
&i2c->iicstat); &i2c->iicstat);
result = WaitForXfer(); result = WaitForXfer(i2c);
if (IsACK()) { if (IsACK(i2c)) {
i = 0; i = 0;
while ((i < addr_len) && (result == I2C_OK)) { while ((i < addr_len) && (result == I2C_OK)) {
writel(addr[i], &i2c->iicds); writel(addr[i], &i2c->iicds);
ReadWriteByte(); ReadWriteByte(i2c);
result = WaitForXfer(); result = WaitForXfer(i2c);
i++; i++;
} }
@ -293,16 +325,17 @@ int i2c_transfer(unsigned char cmd_type,
/* resend START */ /* resend START */
writel(I2C_MODE_MR | I2C_TXRX_ENA | writel(I2C_MODE_MR | I2C_TXRX_ENA |
I2C_START_STOP, &i2c->iicstat); I2C_START_STOP, &i2c->iicstat);
ReadWriteByte(); ReadWriteByte(i2c);
result = WaitForXfer(); result = WaitForXfer(i2c);
i = 0; i = 0;
while ((i < data_len) && (result == I2C_OK)) { while ((i < data_len) && (result == I2C_OK)) {
/* disable ACK for final READ */ /* disable ACK for final READ */
if (i == data_len - 1) if (i == data_len - 1)
writel(readl(&i2c->iiccon) writel(readl(&i2c->iiccon)
& ~0x80, &i2c->iiccon); & ~I2CCON_ACKGEN,
ReadWriteByte(); &i2c->iiccon);
result = WaitForXfer(); ReadWriteByte(i2c);
result = WaitForXfer(i2c);
data[i] = readl(&i2c->iicds); data[i] = readl(&i2c->iicds);
i++; i++;
} }
@ -316,17 +349,18 @@ int i2c_transfer(unsigned char cmd_type,
/* send START */ /* send START */
writel(readl(&i2c->iicstat) | I2C_START_STOP, writel(readl(&i2c->iicstat) | I2C_START_STOP,
&i2c->iicstat); &i2c->iicstat);
result = WaitForXfer(); result = WaitForXfer(i2c);
if (IsACK()) { if (IsACK(i2c)) {
i = 0; i = 0;
while ((i < data_len) && (result == I2C_OK)) { while ((i < data_len) && (result == I2C_OK)) {
/* disable ACK for final READ */ /* disable ACK for final READ */
if (i == data_len - 1) if (i == data_len - 1)
writel(readl(&i2c->iiccon) & writel(readl(&i2c->iiccon) &
~0x80, &i2c->iiccon); ~I2CCON_ACKGEN,
ReadWriteByte(); &i2c->iiccon);
result = WaitForXfer(); ReadWriteByte(i2c);
result = WaitForXfer(i2c);
data[i] = readl(&i2c->iicds); data[i] = readl(&i2c->iicds);
i++; i++;
} }
@ -337,22 +371,24 @@ int i2c_transfer(unsigned char cmd_type,
/* send STOP */ /* send STOP */
writel(I2C_MODE_MR | I2C_TXRX_ENA, &i2c->iicstat); writel(I2C_MODE_MR | I2C_TXRX_ENA, &i2c->iicstat);
ReadWriteByte(); ReadWriteByte(i2c);
break; break;
default: default:
printf("i2c_transfer: bad call\n"); debug("i2c_transfer: bad call\n");
result = I2C_NOK; result = I2C_NOK;
break; break;
} }
return (result); return result;
} }
int i2c_probe(uchar chip) int i2c_probe(uchar chip)
{ {
struct s3c24x0_i2c *i2c;
uchar buf[1]; uchar buf[1];
i2c = get_base_i2c();
buf[0] = 0; buf[0] = 0;
/* /*
@ -360,16 +396,17 @@ int i2c_probe(uchar chip)
* address was <ACK>ed (i.e. there was a chip at that address which * address was <ACK>ed (i.e. there was a chip at that address which
* drove the data line low). * drove the data line low).
*/ */
return i2c_transfer(I2C_READ, chip << 1, 0, 0, buf, 1) != I2C_OK; return i2c_transfer(i2c, I2C_READ, chip << 1, 0, 0, buf, 1) != I2C_OK;
} }
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{ {
struct s3c24x0_i2c *i2c;
uchar xaddr[4]; uchar xaddr[4];
int ret; int ret;
if (alen > 4) { if (alen > 4) {
printf("I2C read: addr len %d not supported\n", alen); debug("I2C read: addr len %d not supported\n", alen);
return 1; return 1;
} }
@ -396,10 +433,11 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
chip |= ((addr >> (alen * 8)) & chip |= ((addr >> (alen * 8)) &
CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW); CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
#endif #endif
if ((ret = i2c = get_base_i2c();
i2c_transfer(I2C_READ, chip << 1, &xaddr[4 - alen], alen, ret = i2c_transfer(i2c, I2C_READ, chip << 1, &xaddr[4 - alen], alen,
buffer, len)) != 0) { buffer, len);
printf("I2c read: failed %d\n", ret); if (ret != 0) {
debug("I2c read: failed %d\n", ret);
return 1; return 1;
} }
return 0; return 0;
@ -407,10 +445,11 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{ {
struct s3c24x0_i2c *i2c;
uchar xaddr[4]; uchar xaddr[4];
if (alen > 4) { if (alen > 4) {
printf("I2C write: addr len %d not supported\n", alen); debug("I2C write: addr len %d not supported\n", alen);
return 1; return 1;
} }
@ -436,8 +475,9 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
chip |= ((addr >> (alen * 8)) & chip |= ((addr >> (alen * 8)) &
CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW); CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
#endif #endif
i2c = get_base_i2c();
return (i2c_transfer return (i2c_transfer
(I2C_WRITE, chip << 1, &xaddr[4 - alen], alen, buffer, (i2c, I2C_WRITE, chip << 1, &xaddr[4 - alen], alen, buffer,
len) != 0); len) != 0);
} }
#endif /* CONFIG_HARD_I2C */ #endif /* CONFIG_HARD_I2C */

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